Electro-hydraulic steering gear system adopted variable frequency speed control strategy, has a characteristic of obvious linear spectrum noise, and it is difficult to attenuate with the changing working condition. Combined with the principle of the electro hydraulic steering mechanism of double redundancy pump source, a pressure ripple control strategy based on the auxiliary pump source confluence was proposed, and it only changed the control system. The theoretical analysis indicates that the pressure ripple of odd harmonics can be attenuated when the two pump sources rotate at the same speed, and the initial phase difference at half cycle. Thus, the master slave synchronization control strategy was adopted, and the corresponding hardware was configured. With the method applying to actual steering gear system, the structure vibration on the pedestal can reduce 3~5 dB, and the first order line spectrum can attenuate 23 dB.